Here's a story I wrote on judoforum.
A lil' background, I was asking them if I should train 2 days a week, per my PE course, or if I should also join the club and make it 5 days a week. There was some argument but overall most said "ask your sensei, don't over do it, but do it fully"

p)
**
So the sensei said "train five days a week!" so I began the mon/wed/fri evenings. The first day was last friday, and there were about 7 beginners and no judo black belts or masters there to teach us, so the yongmudo sensei from the previous hour kept his advanced students there (many of them were trained in judo as well, including the yongmudo chief) and they got as going. It was fun, we mostly did rolls and beginning stuff, and learned a basic trip.
Then today it was totally different. The yongmudo class was out right away, and our sensei showed up. Not the one who teaches the morning class, but his helper, a korean judo champion who speaks about nineteen words of english. There were three of us beginners there to train. Me, a 6'1 (but I slouch) 140 pound guy, a big 6'4" inathletic dude who has less body intuition than I do, and this 5'6" super athletic dude, who didn't have a gi.
Goddamn it was the jam. Even though he couldn't really speak, he got the 50 minutes we had going so fast and so productive. A lil' warmup, some breakfalls we haven't officially learned in the morning PE course (but i already knew from a previous stint) a couple rolls, but mostly we practiced technique. At some point a taekwondo 5th degree fellow (at a place with no belt inflation... not sure if belt inflation even happens that far?) who was also highly proficient in judo came and translated our sensei for us, which helped a lot.
Because I was tall, I kept being pared off with the really tall guy. He has 80+ pounds on me. It ended up being fairly equal because I got about 2/3 of what was going on, he got the other 1/3 (little overlap, weirdly) and he had a size advantage.
Because of the mon/wed/fri sensei, we don't do as strenuous a warmup and we spend our time practicing technique. It's still a work out, though. Anyway, what this tells me is that I'm not likely to burn out because rather than overtraining, I'm just gaining better momentum in my judo study.